Ureido dithiolanes and dithianes

ABSTRACT

IN WHICH R is lower alkyl, R&#39;&#39; is selected from the group consisting of lower alkyl and hydrogen; R1, R2, R3, R4, R5, R6 and R7 each are independently selected from the group consisting of hydrogen and lower alkyl; and n is 0 or 1. These compounds are useful as herbicides.   Substituted ureido dithiolane and dithiane compounds having the formula

United States Patent [1 1 Teach a UREIDO DITHIOLANES AND DITHIANES [75] Inventor: Eugene G. Teach, El Cerrito, Calif.

[73] Assignee: Stautter Chemical Company, New

York, NY.

[22] Filed: Oct. 26, 1971 21 Appl. No.: 192,318

52 us. c1. 260/327 M, 71/9O [51] Int. Cl. C07d 71/00, C07d 73/00 [58] Field of Search 260/327 M, 553 A [56] References Cited UNITED STATES PATENTS 3,461,137 8/1969 Weil et al. 260/327 Primary ExaminerHenry RQ Jiles Assistant Examiner-Cecilia M. Jaisle Attorney-Daniel C. Block et al.

[ Sept. 18, 1973 [57] ABSTRACT Substituted ureido dithiolane and dithiane compounds having the formula in which R is lower alkyl, R is selected from the group consisting of lower alkyl and hydrogen; R,, R R R R R and R each are independently selected from the group consisting of hydrogen and lower alkyl; and n is 0 or 1. These compounds are useful as herbicides.

15 Claims, No Drawings UREIDO DITHIOLANES AND DITHIANES This invention relates to certain novel substituted ureido dithiolanes and dithianes which are useful as herbicides. The compounds of the present invention are new compositions of matter and correspond to the formula in which R is lower alkyl, R is selected from the group consisting of lower alkyl and hydrogen; R R R R R R and R each are independently selected from the group consisting of hydrogen and lower alkyl; and n is 0 or 1.

In the above description, the following preferred embodiments are intended for the various substituents: Lower alkyl preferably includes, unless otherwise provided for, those members which contain from 1 to 6 carbon atoms, inclusive, in both straight chain and branched chain configurations, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiarybutyl, n-pentyl, isopentyl, hexyl, isohexyl.

The compounds of this invention have been found to be active herbicides of a general-type. That is, certain members of the class have been found to be herbicidally effective against a wide range of plant species. A method of controlling undesirable vegetation of the present invention comprises applying an herbicidally effective amount of the above-described compounds to the area or plant locus where control is desired.

An herbicide is used herein to mean a compound which controls or modifies the growth of plants. By a growth controlling amount is meant an amount of compound which causes a modifying effect upon the growth of plants. Such modifying effects include all deviations from natural development, for example, killing, retardation, defoliation, desiccation, regulation, stunting, tillering, stimulation, dwarfing and the like. By plants" it is meant germinant seeds, emerging seedlings, and established vegetation, including the roots and above-ground portions.

The compounds of the present invention are prepared by several different methods, depending upon the nature of the starting materials and products desired. Synthesis of the starting materials can be found in several references in the literature. The following method is illustrative: Meta-nitrobenzaldehyde (wherein R supra, is hydrogen), or metanitroacetophenone or higher phenones (wherein R supra, is lower alkyl), are reacted with a suitable dithiol, either 1,2 or 1,3 dithiol to give the desired cyclic mercaptal. The corresponding mercaptal is reduced by conventional methods to give the corresponding metaamino compound. The meta-amino compound is reacted with an appropriate acyl halide to obtain the desired substituted anilide, dithiolane or dithiane.

Particularly more illustrative of the above generally described method will be the following specific examples. Following the examples is a table of compounds which are prepared according to the procedures described and illustrated herein.

2 EXAMPLE 1 Preparation of intermediates 2(m-nitrophenyl), 3-dithiane One hundred and six-tenths grams (100.6 g.) of mnitro benzaldehyde, 72.4 g. of 1,3-propanedithiol and 1 g. of p-toluene sulfonic acid were combined in 200 ml. of benzene and heated to reflux under a modified Dean-Stark apparatus. The mixture was heated until no more water came off (approximately 12 ml.) and then cooled and the product crystallized. There was obtained a yield of 149 g. of the title compound, m.p. 1l2-114C.

2(m-aminophenyl), 3-tithiane One hundred grams g.) of iron powder was stirred with 250 ml. of ethanol and 200 ml. of water. 7 ml. of concentrated hydrochloric acid was added, and the mixture heated to reflux. One hundred and fortyone grams (141 g.) of 2(m-nitro phenyl)1,3dithiane was added portionwise to maintain reflux. When addition was complete and the mixture had cooled about 10 below reflux, 7 g. of 50 percent sodium hydratevwas added, the mixture filtered through a dicalite pad to remove excess iron and iron oxide and the ethanol solution was removed under vacuum. There was obtained 112.8 g. of the title compound, m.p. l39l42C.

EXAMPLE ll Preparation of 2(m-1-methylureido-3-phenyl)1,3- dithiane Fourteen and eight-tenths grams (14.8 g.) of 2(maminophenyl)l,3-dithiane was dissolved in 100 ml. of acetone, 5 g. of methyl isocyanate was added and the mixture refluxed for 1 hour. The mixture was poured into water and the solid product recovered by filtration and dried. There was obtained a yield of 13.8 g., m.p.

EXAMPLE in 'product taken up in methylene chloride, dried over magnesium sulfate and the solvent removed under vacuum. There was obtained a yield of 15.4 g., n 1.6200.

EXAMPLE 1V Preparation of 2(m-propionamidophenyl)2-methyl- 1,3-dithiolane Twelve and seven-tenths grams (12.7 g.) of 2(maminophenyl) 2-methyl-l,3-dithiolane was dissolved in 100 ml. of acetone, 6.5 g. of triethylamine was added and 5.6 g. of propionyl chloride was added protionwise with cooling. The mixture was poured into water and the oily product taken up in methylene chloride. separated and dried over magnesium sulfate and the solvent removed under vacuum. There was obtained ayield of 13.4 g. of the title compound, u 1.6132.

EXAMPLE V.

Preparation of 2(m-1-butylureido-3-phenyl)- 2- methyl-l ,3-dithiolane EXAMPLE Vl Preparation of 2(m-1,1-dimethylureido-3- phenyl) l ,3-dithiolane Eleven and eight-tenths grams (11.8 g.) of 2(maminophenyl)1,3-dithiolane was dissolved in 100 ml. of

acetone, with 10 g. of anhydrous powdered potassium carbonate and a trace of powdered copper, 6.5 g. of dimethyl carbamyl chloride was added and the mixture was heated at reflux for 8 hours with stirring. The mixture was poured into water and the product taken up in methylene chloride, dried over magnesium sulfate and the solvent stripped off under vacuum. There was obtained a yield of 14.6 g. of the title compound, an oil, u 1.6130.

The following is a table of the compounds which are prepared according to the aforementioned procedures. Compound numbers have been assigned to them and are used for identification throughout the balance of the specification.

TABLE I HERBlClDAL SCREENING TESTS As previously mentioned, the herein-described compounds produced in the above-described manner are phytotoxic compounds which are useful and valuable in controll the growth of various plant species. Compounds of this invention are tested as herbicides in the following manner.

Pre-emergence herbicide test On the day preceding treatment, seeds of seven different weed species are planted in individual rows using one species per row across the width of the flat. The seeds used are hairy crabcrass (Digitaris sanguinalis (L.) Scop.), yellow foxtail Qe taria glauca BeauvJ, watergrass (Echinochloa crusgalli (L.) Beauv.), California red oat (Avena sativa (L.)), redroot pigweed (Amaranthus retroflexlts (L.)), Indian mustard (Brassica juncea (L.) Coss.) and curly dock (Rumex crispus (L.)). Ample seeds are planted to give about 20 to seedlings per row, after emergence, depending on the size of the plants. The flats are watered after plantmg.

The spraying solution is prepared by dissolving 50 mg. of the test compound in 3 ml. of a solvent, such as acetone, water, alcohol or dimethylformamide, containing 1% Tween 20 (polyoxyethylene sorbitan monolaurate). When dimethylformamide is used, only 0.5 ml. or less is used to dissolve the compound. Another solvent is used to make the volume up to 3 ml. The following day after planting, each flat is sprayed at the R: R3 S C r R a C-R C\ k R R4 R /N(fi-NH R 0 Compound R R R] R: R3 R4 R5 17. R5 R1 \I-P C number or my CH H H H H 138-140 CH3 H H H H 1.6328 OH; H H H H 1.6092 H -H H H H 167-168 H H H H H 1.6200 H H H H H 123-125 H H H H H 1.6358 H H H H H 1.6130

Other examples of compounds falling within the generic formula presented herein, which are preparable by the aforedescribed procedures and which may be rate of 20 pounds of the candidate compound per 143 gallons of solution per acre. An atomizer is used to spray the solution onto the soil surface. The flats are formulated into herbicidal compositions and applied as placed in a greenhoust at 85F. and watered reguherein illustrated, are:

larly by sprinkling. Two weeks after treatment, the de- R, 71 Re R1 CH3 0 CH3 0 CH 0 0 H 0 H 0 H O H 1 CH3 II 1 OH: H 1 CH3 H 1 CH H 1 H OH: H 1 H H H 1 H H H 1 H H H 1 C113 Calls H 1 CH3 CH3 H 1 n-C H n-C4II9 H 1 CH 11-C3H1 gree of weed control is determined by comparing the amount of germination and growth ofeach weed in the treated flats with weeds in several untreated control flats. The rating system is as follows:

0 no significant injury (approximately 0-l0 per cent control) 3 slight injury (approximately -40 per cent control) 6 moderate injury (approximately 40-70 per cent control) 9 severe injury or death (approximately 70-100 percent control) An activity index is used to represent the total activity on all seven weed species. The activity index is the sum of the numbers divided by 3, so that an activity .index of 21 represents complete control of all seven weeds. The results of this test are reported in Table ll.

Post-emergence herbicide test Seeds of five weed species, including hairy crabgrass, watergrass, California red oats, Indian mustard, and curly dock and one crop, pinto beans (Phaseolus vulgaris), are planted in flats and described above for preemergence screening. The flats are placed in the greenhouse at 72-85F. and watered daily with a sprinkler. About 10 to 14 days after planting, when the primary leaves of the bean plant are almost fully expanded and the first trifoliate leaves are just starting to form, the plants are sprayed. The spray is prepared by weighing out 50 mg. of the test compound, dissolving it in 5 ml. of acetone containing l% Tween (polyoxyethylene sorbitan monolaurate) and then adding 5 ml. of water. The solution is sprayed on the foliage using an atomizer. The spray concentration is 0.5 percent and the rate would be approximately 20 lb/acre if all of the spray were retained on the plant and the soil, but some spray is lost so it is estimated that the application rate is approximately 12.5 lb/acre.

Beans are used to detect defoliants and plant growth regulators. The beans are trimmed to two or three plants per flat by cutting off the excess weaker plants several days before treatment. The treated plants are placed back in the greenhouse and care is taken to avoid sprinkling the treated foliage with water for three days after treatment. Water is applied to the soil by means of a slow stream from a watering hose taking care not to wet the foliage.

Injury rates are recorded 14 days after treatment.

The rating system is the same as described above for the pre-emergence test where (0), (3), (6), and (9) are used for the different rates of injury and control. The injury symptoms are also recorded. The maximum activity index for complete control of all the species in the post-emergence screening test is l8.This index represents the sum of the rating numbers obtained with the six plant species used in the test divided by 3. The herbicide activity index is shown in Table II.

TABLE II l-lerbicidal Activity Screening Results I lle'rbicidal Activity lndex** 6 0 3 7 0 13 s s l6 21 -|00% control of all seven plant species tested preemergence. 18 70-l00% control of all six plant species tested post-emergence.

The compounds of the present invention are used as pre-emergence or post-emergence herbicides and are applied in a variety of ways at various concentrations. In practice, the compounds are formulated with an inert carrier, utilizing methods well-known to those skilled in the art, thereby making them suitable for application as dusts, sprays, or drenches and the like, in the form and manner required. The mixtures can be dispersed in water with the aid of a wetting agent or they can be employed in organic liquid compositions, oil and water, water in oil emulsions, with or without the addition of wetting, dispersing or emulsifying agents. An herbicidally effective amount depends upon the nature of the seeds or plants to be controlled and the rate of application varies from I to approximately 50 pounds per acre.

The phytotoxic compositions of this invention employing an herbicidally effective amount of the compound described herein are applied to the plants in the conventional manner. Thus, the dust and liquid compositions can be applied to the plant by the use of powerdusters, boom and hand sprayers and spray-dusters. The compositions can also be applied from airplanes as a dust or a spray because they are effective in very low dosages. In order to modify or control growth of germinating seeds or emerging seedlings, as a typical example, the dust and liquid compositions are applied to the soil according to conventional methods and are destributed in the soil to a depth of at least ,5 inch below the soil surface. It is not necessary that the phytotoxic compositions be admixed with the soil particles and these compositions can be applied merely by spraying or sprinkling the surface of the soil. The, phytotoxic compositions of this invention can also be applied by addition to irrigation water supplied to the field to be treated. This method of application permits the penetration of the compositions into the soil as the water is absorbed therein. Dust compositions, granular compositions or liquid formulations applied to the surface of the soil can be distributed below the surface of the soil by. conventional means such as discing, dragging or mixing operations.

The phytotoxic compositions of this invention can also contain other additaments, for example, fertilizers, pesticides and the like, used as adjuvant or in combination with any of the above-described adjuvants. Other phytotoxic compounds useful in combination with the abovedescribed compounds include, for example, 2,4-dichlorophenoxyacetic acids, 2,4,5-trichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid and the salts, esters and amides thereof; triazine derivatives, such as 2,4-bis (3-methoxypropylamino)- 6-methyl-thio-S-triazine; 2-chloro-4-ethylamino-6-isopropylamino-S-triazine, and 2-ethylamino-4- isopropylamino-6-methylmercapto-S-triazine, urea derivatives, such as 3-(3,4-dichlorophenyl)-l,l-dimethyl urea and 3-(p-chlorophenyl)-l,l-dimethyl urea and acetamides such as N,N-diallyl-achloroacetamide, N- (a-chloroacetyl)hexamethylene imine, and N,N-diethyl-a-bromacetamide, and the like; benzoic acids such as 3-amino-2,5-dichlorobenzoid; and thiocarbamates. such as S-propyl dipropylthiocarbamate; S-ethyldipropylthiocarbamate, S-ethylcyclohexyl-ethylthiocarbamate, S-ethyl hexahydro-lH-azepine-l-carbothioate and the like. Fertilizers useful in combination with the active ingredients include, for example, ammonium nitrate, urea and superphosphate. Other useful additaments include materials in which plant organisms take root and grow, such as compost, manure, humus, sand and the like.

The concentration of a compound of the present invention, constituting an effective amount in the best mode of administration in the utility disclosed, is readily determinable by those skilled in the art.

Various changes and modifications are possible without departing from the spirit and scope of the invention described herein and will be apparent to those skilled in the art to which it pertains. It is accordingly intended that the present invention shall only be limited by the scope of the claims.

What is claimed is:

in which R is lower alkyl, R is selected from the group consisting of lower alkyl and hydrogen; R,, R R R R R and R-, each are independently selected from the group consisting of hydrogen and lower alkyl; and n is 0 or 1.

2. A combdirfiifcbrdiii ib claim 1 in which R is lower alkyl, R' is hydrogen, R, is lower alkyl and R R R, and R are each independently hydrogen, and n is 0. I 3. A compound according to claim 2 in which R is methyl and R, is methyl.

4. A compound according to claim 2 in which R is nbutyl and R, is methyl.

5. A compound according to claim 1 in which R is lower alkyl, R is lower alkyl, R, is lower alkyl, R,, R R and R, are each independently hydrogen, and n is 0.

6. A compound according to claim 5 in which R is methyl, R is methyl and R, is methyl.

7. A compound according to claim 1 in which R is lower alkyl, R, R,, R R R, and R are each independently hydrogen, n is 1, R is hydrogen and R is hydrogen.

8. A compound according to claim 7 in which R is methyl.

9. A compound according to claim 7 in which R is nbutyl.

10. A compound according to claim 1 in which R is lower alkyl, R is lower alkyl, R,, R R R and R are each independently hydrogen, n is 1, R is hydrogen and R, is hydrogen.

11. A compound according to claim 10 in which R is methyl and R is methyl.

12. A compound according to claim 1 in which R is lower alkyl, R is hydrogen, R,, R R,,, R, and R are each independently hydrogen and n is 0.

13. A compound according to claim l2 in which R is methyl.

14. A compound according to claim 1 in which R is lower alkyl, R is lower alkyl, R,, R R;,, R, and R are each independently hydrogen and n is 0.

15. A compound according to claim 14 in which R is methyl and R is methyl. 

2. A compound according to claim 1 in which R is lower alkyl, R'' is hydrogen, R1 is lower alkyl and R2, R3, R4 and R5 are each independently hydrogen, and n is
 0. 3. A compound according to claim 2 in which R is methyl and R1 is methyl.
 4. A compound according to claim 2 in which R is n-butyl and R1 is methyl.
 5. A compound according to claim 1 in which R is lower alkyl, R'' is lower alkyl, R1 is lower alkyl, R2, R3, R4 and R5 are each independently hydrogen, and n is
 0. 6. A compound according to claim 5 in which R is methyl, R'' is methyl and R1 is methyl.
 7. A compound according to claim 1 in which R is lower alkyl, R'', R1, R2, R3, R4 and R5 are each independently hydrogen, n is 1, R6 is hydrogen and R7 is hydrogen.
 8. A compound according to claim 7 in which R is methyl.
 9. A compound according to claim 7 in which R is n-butyl.
 10. A compound according to claim 1 in which R is lower alkyl, R'' is lower alkyl, R1, R2, R3, R4 and R5 are each independently hydrogen, n is 1, R6 is hydrogen and R7 is hydrogen.
 11. A compound according to claim 10 in which R is methyl and R'' is methyl.
 12. A compound according to claim 1 in which R is lower alkyl, R'' is hydrogen, R1, R2, R3, R4 and R5 are each independently hydrogen and n is
 0. 13. A compound according to claim 12 in which R is methyl.
 14. A compound according to claim 1 in which R is lower alkyl, R'' is lower alkyl, R1, R2, R3, R4 and R5 are each independently hydrogen and n is
 0. 15. A compound according to claim 14 in which R is methyl and R'' is methyl. 